| CTM-3TBD: General | |||
| Date of first acceptance | 1941 | Total acceptances | 5 |
| Manufacturer | Marmon-Herrington Co. | Crew | 3 men |
| CTM-3TBD: Dimensions | |||
| Combat weight | 20,800lbs 9,430kg |
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| CTM-3TBD: Armament | |||
| Type | Mount | Traverse | Elevation |
| Two .50cal MG | Turret | 360° (manual) |
Manual |
| Three .30cal MG | Ball mounts in hull | Manual | Manual |
| CTM-3TBD: Armor | |
| Maximum | .5" 1.3cm |
| Minimum | .4375" 1.111cm |
| CTM-3TBD: Automotive | |||||
| Engine | Hercules DXRB diesel | ||||
| Horsepower | 123 | ||||
| CTM-3TBD: Suspension | ||
| Type | Road wheels | Track return rollers |
| Vertical volute spring | 2 bogies/track; 2 wheels/bogie |
2/track |
| Drive sprockets | Idlers | Shock absorbers |
| 14-tooth front drive | Adjustable at rear of track | None |
| CTM-3TBD: Track | |||
| T16E1 | |||
| Outside guide, double pin, rubber bushed, reversible rubber | |||
| Width | 11.6" 29.5cm |
Pitch | 5.5" 14cm |
| T16E2 | |||
| Outside guide, double pin, rubber bushed, non-reversible rubber | |||
| Width | 11.6" 29.5cm |
Pitch | 5.5" 14cm |
| CTM-3TBD: Performance | |||
| Max level road speed | 30mph 50kph |
Cruising range | 125mi 201km |
The five CTM-3TBDs accepted by the US Marine Corps essentially placed a turret onto the top of Marmon-Herrington's earlier light tank designs, using vertical volute spring suspension bogies similar to those found on Army light tanks and those tanks' tracks. For subsequent designs, the Corps asked for a turret with one gun instead of the CTM-3TBD's twin arrangement. The engine louvres were .25" (.64cm) thick.